The present invention is a new variety of the mint species Mentha canadensis (common name American cornmint/Japanese peppermint). The essential oil industry refers to some members of the Mentha canadensis species as “Mentha arvensis.” This includes such popular varieties as ‘Shivalik,’ ‘Kosi,’ and ‘Kalka.’ Botanically, however, these plants are M. canadensis species, with Mentha arvensis being a different and significantly less commercial mint species commonly referred to as a cornmint. The botanical differences allow one to differentiate between the two species through the use of current botanical keys for the genus Mentha. The use of “Mentha arvensis” by the industry should be interpreted as a colloquial industry usage for an “oil type” and not one of botanical specificity as these plants are correctly botanically identified as M. canadensis. For further information on mint species, see Lawrence, B. ed., 2007. Mint: The Genus Mentha. CRC Press, Boca Raton, Fla.; see also Tucker, A.O. and T. Debaggio, 2000. The Big Book of Herbs. Interweave Press, Inc., Loveland, Colo.
The new mint plant of the present invention was developed in an effort to cultivate a mint variety having a peppermint type oil and flavor profile, and greater tolerance to Verticillium wilt (Verticillium dahliae) and mint rust (Puccinia menthae) compared to that of commercial peppermint (Mentha piperita). Furthermore, ‘Metolius’ produces a peppermint-type oil that varies minimally in oil profile based on plant maturity.
The inventors explored ways of creating genetically distinct mint plants through somatic hybridization of unpatented varieties of Mentha canadensis and Mentha piperita. In 2002 ‘Metolius’ was created using this method. Specifically, the parental stock that was used to create ‘Metolius’ consisted of unpatented germplasms of Mentha×piperita and Mentha canadensis species. The features of ‘Metolius’ are compared to the parent Mentha canadensis. 
Since 2002, the plant has been under continuous evaluation at the Applicants' facilities in Eugene, Oreg. and Sunnyside, Wash., as well as under small-scale commercial programs located in Idaho, Washington, and Eastern Oregon. Asexual propagation through stem and rhizome cuttings have been successfully carried out many times in Eugene, Oreg. and Sunnyside, Wash. The resulting propagules have remained stable in appearance, oil quality, and other characteristics to the original plant.